The well known scientist who is known for saying, "God does not play dice with the universe" is Albert Einstein. Next to understand this quote, one must understand two underlying concepts. First, Einstein has pointed to the fact that quantum mechanical (QM) equations are deterministic even though they look probabilistic. Others say that interpretations of QM that point to the so called 'many worlds' use decoherence and pilot wave to provide deterministic solutions.

Then, there is Viktor T. Toth's answer to the question: Is The Many-Worlds Interpretation of QM deterministic? Does quantum mechanical decoherence really make physics deterministic? Have scientists been interpreting QM wrongly the whole time? Physicist John Stewart Bell's work seemed to rule out local hidden variables. In the end, the conclusion that local hidden variables can't exist relied mainly upon an assumed suggestion and interpretation.

Without any dice, what's happening in the universe could be likened to the ongoing computation of some ginormous fractal. As Max Tegmark suggested the universe could only be a mathematical object, more an algorithmic process than a thing.

But the universe was one thing for Einstein. According to Einstein, man is not separate from the universe. "If you think he is, it is an illusion." It was written that Einstein subscribed to idea that 'all is God'. "Even if the universe has an outside, this too is united to God. Seeing them as two items, creates an illusion."

More Info: en.wiktionary.org